With increasing attention toward global environmental consciousness, especially in energy saving and carbon reduction, green energy (such as solar power, wind power, wave power, hydrogen energy or biomass energy) is becoming a focal point for industries all over the world, since it can be extracted, generated, and/or consumed without any significant negative impact to the environment. Among the variety of forms of green energy, wind power is the one most likely to become a major alternative energy source in the near future.
The harvesting of wind power is enabled through the use of windmills. Generally, a windmill is composed of: a tower, arranged at a specific location conforming to certain conditions; a gear box, mounted to an end of the tower; a generator, mounted at the end of the tower alongside the gear box to allow the same to be driven by the gear box so as to generate electricity; and a blade module, coupled to the gear box by a bearing for allowing the gear box to be driven by the blade module. The blade module is configured with a plurality of blades in a manner that each blade is coupled to the bearing while the bearing is further coupled to a hub. It is noted that there can be sealing components respectively arranged at a position between the blades and the bearing, and also at a position between the bearing and the hub.
Operationally, when the blades in the blade module are driven to rotate by wind power, the bearing will be brought along to rotate so as to drive the hub to rotate as well, and then the rotation of the hub is transmitted to the generator through the gear box to enable the generator to generate electricity. Simultaneously, the rotation of the plural blades can be adjusted and controlled by the use of a pitch motor for achieving maximum wind power harvesting, as the pitch motor is connected to an internal ring gear embedded in the bearing through the coupling of a small gear. However, if there is no sealing means arranged at the interface (or interval) between the inner ring of the bearing and the blades, and between the outer ring of the bearing and the hub, for preventing water or foreign objects from entering into the hub through those interfaces, the electric control equipment arranged inside the hub might be in danger of being damaged and thus beginning to malfunction. Consequently, the hub is usually sealed by a kind of sealing apparatus to be used for preventing water from entering and also for preventing leakage of internal lubricating oil. Ideally, the hub can be sealed satisfactorily by a conventional sealing apparatus. In reality, however, the sealing effect of the conventional seal apparatus can easily be devastated by material failure, inferior working conditions or a harsh environment.
Existing windmills with a water-proof seal design are inflexible because the conventional sealing apparatus cannot easily be detached or replaced. Nor can such conventional apparatus be adapted to many windmills available on the market today.